1. Technical Field
This disclosure relates to a drive transmitter, a driving device incorporating the drive transmitter, and an image forming apparatus incorporating the driving device.
2. Related Art
An electrophotographic image forming apparatus includes rotary bodies such as a photoconductor and a developing roller, and forms an image by driving the rotary bodies for rotation. Many of the rotary bodies are designed to be detachably attached to an apparatus body for the purpose of replacement. Hence, a drive transmitter that transmits driving force from a drive source of the apparatus body to the rotary body is provided with a coupling as a drive transmitter that connects both of them detachably.
A known coupling that functions as a drive transmitter includes a drive joint that functions as a drive coupling provided at an end of a drive output shaft, and a driven joint that functions as a driven coupling provided at an end of a rotation shaft, which is a driven shaft, of a drive target rotator. When the drive joint transmits the driving force to the driven joint, a drive claw provided to the drive joint and projecting in the axial direction comes into contact with a driven claw, which projects in the axial direction, of the driven joint to transmit the driving force to the driven joint.
The drive claw of the drive joint projects in the axial direction from a drive base mounted on the drive output shaft of the drive joint, and has a predetermined length in the rotation direction. A drive transmission portion that transmits a driving force at one end of the drive claw in the rotation direction in contact with the driven claw is a face perpendicular to the rotation direction. Moreover, the drive claw gradually reduces the height in the axial direction from the one end to the other end in the rotation direction. In other words, a far end face of the drive claw, which is an opposing face opposed to the driven joint, is an inclined face. The drive joint is provided with two drive claws having the above-described, spaced 180 degrees apart in the rotation direction.
When the drive target rotator is moved in the axial direction to attach the drive target rotator to the apparatus body, the driven coupling provided at the end of the rotation shaft of the drive target rotator approaches the drive coupling in the axial direction. The driven claws of the driven coupling then enter between the drive claws of the drive coupling.
Generally, the drive joint that functions a drive coupling and the driven joint that functions a driven coupling normally have the same shape in terms of costs and the like.